A Further Study of Inconsistencies between Autoignition and Knock Intensity in the CFR Octane Rating Engine 2005-01-2081
Careful consideration of the development and operation of the ASTM knock detection system on the Cooperative Fuels Research (CFR) octane rating engine has shown that the pressure fluctuations, brought about by autoignition of the end-gas, do not contribute to measurement of knock intensity. The analyses of a variety of fuels at standard knock intensity revealed that knock intensity measured on the CFR engine is related to the rate of change of pressure prior to knocking and is consistent with the description and operation of, not only the original bouncing pin, but also the modern day electronic CFR knock measurement system. It was concluded that the use of octane number data to directly infer information about the autoignition behaviour of fuels should be done with caution.
Citation: Swarts, A., Yates, A., Viljoen, C., and Coetzer, R., "A Further Study of Inconsistencies between Autoignition and Knock Intensity in the CFR Octane Rating Engine," SAE Technical Paper 2005-01-2081, 2005, https://doi.org/10.4271/2005-01-2081. Download Citation
Andre Swarts, Andy Yates, Carl Viljoen, Roelof Coetzer
Sasol Advanced Fuels Laboratory, University of Cape Town, Cape Town
2005 SAE Brasil Fuels & Lubricants Meeting
SAE 2005 Transactions Journal of Fuels and Lubricants-V114-4